Cython
Cython: An open-source compiler for Python projects that need native C or C++ extensions. Ranked #4 of 28 in Code Transpilers by our editors (8.7/10); pricing: Free plan; best for python projects needing C or C++ extensions.
At a glance
- Editor score8.7 / 10
- PricingFree plan
- Best forPython projects needing C or C++ extensions
- Free planYes
- Paid fromFree
- Intermediate outputNo
- Conversion modeSource-to-source
- Facts checked22 Sep 2026
Where it wins
- Translates Python and Cython source into C or C++ code
- Supports optional static types and C/C++ interoperability
- Works with Jupyter and build tools including setuptools and Meson
Where it doesn't
- Requires a native build step to create importable extension modules
- Focused on Python-to-C/C++ compilation rather than general-purpose conversion
- Community and documentation are the listed support channels
Our verdict on Cython
Cython is an open-source programming language and static compiler for Python developers building compiled extension modules or connecting Python code to C and C++ libraries. It translates Python or Cython source into C or C++ code, which can then be compiled into importable Python extensions. The optional static type declarations let projects specify Python and C types, while support for pure Python syntax gives teams a way to work with Python code as well as Cython syntax. It is aimed at projects where native code interoperability is part of the development need, rather than general-purpose source conversion.
Its compilation workflow spans command-line use through cython and cythonize, programmable compilation through cython.inline, cython.compile, and cythonize, and Jupyter Notebook compilation. C++ support includes templates and overloaded functions. The ecosystem connections are useful for projects already using CPython or PyPy, NumPy, and build tooling such as setuptools, Meson, CMake, or hatchling. That breadth makes it relevant across varied Python development setups, though the result still needs to be built into an extension module; it is not simply a standalone Python runtime replacement.
Cython is freely available under the Apache 2.0 License, with self-hosted deployment and community and documentation support. Its strengths are concentrated in Python-to-native compilation and C/C++ interoperability, so it fits developers prepared to incorporate compilation and native libraries into their workflow. Teams seeking a cloud-hosted conversion service, a managed paid support offering, or a broader transpiler for unrelated languages should look elsewhere. Python projects that need importable extensions and already work with native build tools are the clearest fit.
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Cython pricing
Cython fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Source languages | Not verified |
| Target languages | Not verified |
| Syntax-version conversion | No |
| Intermediate output | No |
| CLI access | Yes |
| API access | Yes |
| Conversion mode | Source-to-source |
| Deployment | Self-hosted |
| Platforms | Windows, macOS, Linux |
| Support | Community, Docs |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 10 integrations: CPython, PyPy, C, C++, NumPy, Jupyter Notebook … |
| Pricing | Free plan |
| Website | cython.org |
| Facts checked | 22 Sep 2026 |
Cython integrations
Cython lists 10 integrations on its own site.
- CPython
- PyPy
- C
- C++
- NumPy
- Jupyter Notebook
- setuptools
- Meson
- CMake
- hatchling
Alternatives to Cython
- BabelFlexible ECMAScript transforms with CLI, Node.js APIs, and browser compilation.9.3
- SWCAn open-source compiler with minification and bundling for JavaScript and TypeScript workflows.9.2
- Kotlin/JSA free Kotlin-to-JavaScript toolchain for browser and Node.js projects.8.8
Cython vs the competition
- Cython vs Babel
- Cython vs SWC
- Cython vs Kotlin/JS
- Cython vs TeaVM
- Cython vs Google Web Toolkit
- Cython vs ClojureScript
Compare Cython with any tool side by side →
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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